Mitt Romney was a shrewd businessman, a skilled governor and an Olympic turnaround master, but on Tuesday his six-year quest for the presidency came to a crushing end.

Despite the sluggish economy and a conservative backlash against President Barack Obama, Romney failed to build on his victory in a hard-fought Republican primary or to alter the political map with a late tack to the center.

A win would have made him the country's first Mormon president and marked a dramatic comeback from his 2008 primary defeat to Senator John McCain.

Instead, the loss will likely mark the end of a political career that began with a failed 1994 Senate run but saw Romney go on to become the governor of Massachusetts and the flag-bearer of a Republican Party slow to warm to him.

Romney, 65, argued that the management skills that made him so effective in business as he amassed a huge fortune and saved the Salt Lake City Olympics from ruin made him the ideal candidate to steer the country back to prosperity.

But he struggled to counter the image that was stuck on him in the primary battles and beyond -- that of a policy flip-flopper with awkward social skills and questionable concern for America's struggling middle class.

When Romney presented himself as a skilled manager with impressive business acumen his opponents countered that he was a cut-throat capitalist raider, and when he projected pragmatic moderation critics saw only deceitful opportunism.

Throughout the roller-coaster primaries, rivals struggled to land telling blows on the former Boston venture capitalist, who managed to stay above the fray while giving off the air of an inevitable nominee.

Despite lingering doubts about his opposition on hot-button social issues like gay marriage and abortion, he handily won the nod of his conservative party as the candidate with the best chance of beating Obama.

But early in the campaign the multimillionaire businessman demonstrated a tin ear with a string of wealth-related gaffes -- including challenging Texas Governor Rick Perry to a $10,000 bet during a debate -- that made it all too easy for opponents to portray him as out of touch with ordinary Americans.

Romney's image received a carefully scripted makeover at the convention in Tampa, Florida, as he tried close the yawning likability gap between himself and Obama.

His wife Ann invoked their love story as high school sweethearts to show the human side of a man whose ram-rod straight bearing is lampooned as too stiff, whose hair was never even slightly mussed.

The couple's squeaky-clean and loving family life -- they have been married 43 years and have five sons and 18 grandchildren -- was thought to be a clear vote-winner.

Mitt was born into wealth and privilege in Detroit in 1947, the son of George Romney, who served as Michigan governor and chairman of American Motors.

George Romney tried and failed his own presidential bid, briefly emerging as a top contender for the 1968 Republican nomination before losing to Richard Nixon.

His son was often at his side while campaigning for the governorship, but for two years Mitt's Mormon faith took him to France as a religious missionary.

It was there in 1968 that tragedy struck. Romney had been driving members of the Mormon church when another car slammed into their Citroen. A passenger was killed and Romney himself nearly died.

But he recovered and returned to the United States and to Ann, whom he married months later.

As a rising star with Harvard degrees in law and business, he joined Bain & Company in 1977, where he so impressed the chief executive that in 1984 he was entrusted with heading the new venture capital arm, Bain Capital.

Romney ran the firm for 15 years, earning spectacular wealth and laying the groundwork for a political career that from the beginning seemed geared toward the national stage.

During his 2003 to 2007 governorship of Massachusetts, he built a reputation as a moderate deal-maker and allied with Democratic state lawmakers to gave birth to the nation's first universal healthcare program.

But after losing the 2008 nomination to McCain, he distanced himself from his crowning gubernatorial achievement, as the program served as a model for the nationwide plan created by Obama in 2010, which most Republicans despise.

That fit seamlessly into the narrative perpetuated by White House attack ads -- that Romney has undertaken a wholesale reversal of many positions for political gain.

Initially "pro-choice," Romney switched to become anti-abortion after being elected governor. He made a similar about-face on gay rights.

He raised eyebrows among conservatives when he said in early October that he could not foresee supporting any new law restricting women's rights to abortion, but rowed back the next day, pledging to be a "pro-life president."

Romney faced opprobrium for comments that surfaced in August in a video that showed him disparaging "47 percent" of voters as government-beholden victims.

The remarks threatened to be his undoing, until his command performance in his first debate with a lackluster Obama.

But the momentum slowed weeks later as the devastating cyclone Sandy blew the campaign off course and allowed Obama to project leadership at the head of a multi-state disaster response.

On Tuesday morning polls had the candidates locked in a virtual tie, but by shortly after 11:00 pm (0400 GMT), US TV networks had projected a decisive win for Obama.